SB 5.14.21

kadācid bhagna-māna-daṁṣṭro durjana-danda-śūkair alabdha-nidrā-kṣaṇo vyathita-hṛdayenānukṣīyamāṇa-vijñāno ’ndha-kūpe ’ndhavat patati.
Synonyms: 
kadācit — sometimes; bhagna-māna-daṁṣṭraḥ — whose teeth of pride are broken; durjana-danda-śūkaiḥ — by the envious activities of evil men, who are compared to a kind of serpent; alabdha-nidrā-kṣaṇaḥ — who does not get an opportunity to sleep; vyathita-hṛdayena — by a disturbed mind; anukṣīyamāṇa — gradually being decreased; vijñānaḥ — whose real consciousness; andha-kūpe — in a blind well; andha-vat — like illusion; patati — he falls down.
Translation: 
In the forest of the material world, the conditioned soul is sometimes bitten by envious enemies, which are compared to serpents and other creatures. Through the tricks of the enemy, the conditioned soul falls from his prestigious position. Being anxious, he cannot even sleep properly. He thus becomes more and more unhappy, and he gradually loses his intelligence and consciousness. In that state he becomes almost perpetually like a blind man who has fallen into a dark well of ignorance.